U.S. patent application number 13/367426 was filed with the patent office on 2012-08-09 for devices, systems and methods for reducing an emission from a combustion reaction.
This patent application is currently assigned to DOW GLOBAL TECHNOLOGIES LLC. Invention is credited to David H. BANK, Andrey N. SOUKHOJAK.
Application Number | 20120198821 13/367426 |
Document ID | / |
Family ID | 45688249 |
Filed Date | 2012-08-09 |
United States Patent
Application |
20120198821 |
Kind Code |
A1 |
SOUKHOJAK; Andrey N. ; et
al. |
August 9, 2012 |
DEVICES, SYSTEMS AND METHODS FOR REDUCING AN EMISSION FROM A
COMBUSTION REACTION
Abstract
The invention is directed at systems and process for reducing or
eliminating the emissions of one or more undesirable substances.
The systems include a heat storage device an emission reduction
device, one or more valves, and one or more exit points.
Inventors: |
SOUKHOJAK; Andrey N.;
(Midland, MI) ; BANK; David H.; (Midland,
MI) |
Assignee: |
DOW GLOBAL TECHNOLOGIES LLC
Midland
MI
|
Family ID: |
45688249 |
Appl. No.: |
13/367426 |
Filed: |
February 7, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61440541 |
Feb 8, 2011 |
|
|
|
Current U.S.
Class: |
60/274 ;
60/297 |
Current CPC
Class: |
Y02E 60/145 20130101;
F01N 2240/10 20130101; F01N 3/035 20130101; F01N 2240/36 20130101;
Y02E 60/14 20130101; F01N 3/2882 20130101; F28D 9/0012 20130101;
F01N 2410/02 20130101; Y02T 10/12 20130101; F01N 3/2006 20130101;
F28D 20/023 20130101; F28F 2265/26 20130101; F01N 3/2093 20130101;
F01N 2510/06 20130101; F01N 3/2053 20130101; Y02T 10/26
20130101 |
Class at
Publication: |
60/274 ;
60/297 |
International
Class: |
F01N 3/20 20060101
F01N003/20 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 6, 2012 |
US |
PCT/US12/23935 |
Claims
1. A system for reducing the amount of one or more undesirable
substances in a flow of a fluid from the discharge of an emission
source, the system comprising: a. an emission reduction device
capable of reducing a quantity of the undesirable substance,
wherein the undesirable substance includes an undesirable chemical,
an undesirable particle, or both; b. a heat storage device
including a thermal energy storage material; c. one or more valves
for controlling the flow of the fluid; and d. one or more exit
points; wherein the system includes a sufficient number of valves
that are positioned with respect to the emission reduction device,
the heat storage device and the exit point so that the system is
capable of operating in at least two modes including: i) a warm-up
mode, wherein the emission reduction device, the heat storage
device, and at least one of the valves are in fluid communication
with each other and at least some of the flow of the fluid passes
through the heat storage device prior to passing through the
emission reduction device, wherein thermal energy is removed from
the heat storage device: and ii) a charging mode wherein the
emission source, the emission reduction device, the heat storage
device, at least one exit point, and at least one valve are in
fluid communication with each other; and the heat storage device
receives heat from the flow of the fluid from the discharge of the
emission source.
2. The system of claim 1, wherein the system includes a sufficient
number of valves that are positioned with respect to the emission
reduction device, the heat storage device and the exit point so
that the system is capable of operating in at least three modes
including a by-pass mode wherein the emission reduction device, at
least one of the one or more exit points and at least one of the
one or more valves are in fluid communication with each other, the
flow of the fluid passes through at least the emission reduction
device, the flow substantially by-passes the heat storage device,
and the flow is discharged from the one or more exit points.
3. The system of claim 2, wherein during the first charging mode at
least some of the flow of the fluid passes through the emission
reduction device prior to passing through the heat storage device,
and is discharged from the one or more exit points, and
4. The system of claim 3, wherein the undesirable substances
includes one or more undesirable chemicals; and the heat storage
device includes a catalyst capable of reducing the amount of the
one or more undesirable chemicals.
5. The system of claim 2, wherein during the second charging mode a
portion of the flow of the fluid passes through the heat storage
device prior to passing through the emission reduction device,
wherein the amount of the one or more undesirable substances in the
first portion is first reduced in the emission reduction device,
and a different portion of the flow of the fluid passes through the
emission reduction device without passing through the heat storage
device.
6. The system of claim 2, wherein the thermal energy storage
material of the heat storage device has a liquidus temperature from
about 80.degree. C. to about 350.degree. C.
7. The system of claim 2, wherein the thermal energy storage
material has a heat storage density of about 1 MJ/liter or more
when heated from about 80.degree. C. to about 350.degree. C.
8. The system of claim 2, wherein i) the one or more valves
includes a valve having multiple flow paths, ii) the one or more
valves includes a diverter valve having at least a first inlet and
at least two outlets, wherein the diverter valve is capable of
decreasing the flow from one outlet of the diverter and increasing
the flow from a second outlet of the diverter valve.
9. The system of claim 2, wherein the system includes a circulating
device for circulating a fluid from the heat storage device to the
emission reduction device during the warm-up mode.
10. The system of claim 2, wherein the emission source is an
internal combustion engine; the emission reduction device is a
catalytic converter of a vehicle; at least one of the exit points
is in fluid connection with a muffler; the flow of the fluid passes
through the muffler after passing through the heat storage device
during the charging mode; and the fluid is a vehicle exhaust.
11. The system of claim 10, wherein the system is capable of
operating in the by-pass mode, and the flow of the fluid passes
through the muffler after passing through the emission reduction
device during the charging mode and during the by-pass mode.
12. The system of claim 1, wherein the heat storage device is
sufficiently insulated so that it maintains a temperature of at
least about 100.degree. C. when the thermal energy storage material
is heated to about 300.degree. C. and then exposed to an ambient
temperature of about 25.degree. C. for about 24 hours.
13. The system of claim 2, wherein the system includes a sufficient
amount of thermal energy storage material so that the system is
capable of reducing the emissions of carbon monoxide discharged
from the system during the first 30 seconds after cold starting an
emission source by at least about 20% compared to a system without
a heat storage device for heating the emission reduction device and
only uses the heat directly from the emission source and carried by
the emissions to heat the catalytic converter, wherein the cold
starting occurs when the ambient temperature, the initial
temperature of the emission source, and the initial temperature of
the emission reduction device are all about 25.degree. C.
14. The system of claim 2, wherein the undesirable substances
includes one or more undesirable chemicals; and wherein the
undesirable chemicals include one or more hydrocarbons, one or more
nitrogen oxides, carbon monoxide, or any combination thereof; and
the fluid is an exhaust gas generated by a process that includes
burning of a hydrocarbon fuel.
15. The system of claim 1, wherein the thermal energy storage
material is sealed in one or more capsules contained in the heat
storage device.
16. A process comprising the steps of: i) cold starting an emission
source in fluid connection with the system of claim 2, to generate
the fluid including the one or more undesirable chemicals; and ii)
passing at least a portion of the flow of the fluid through the
heat storage device prior to passing the portion of the flow of the
fluid through the emission reduction device during the cold
starting operation wherein the temperature of the emission
reduction device is below a predetermined minimum operating
temperature.
17. The process of claim 16 wherein the process includes a step of
changing one or more of the valves after the temperature of the
emission reduction device reaches a predetermined minimum operating
temperature so that the flow of the fluid passes through the
emission reduction device prior to any flow of the fluid through
the heat storage device.
18. The process of claim 17 wherein the process includes a step of
increasing the temperature of the thermal energy storage material
using heat from the fluid.
19. The process of claim 18, wherein the process comprises a step
of changing one or more of the valves after the temperature of the
thermal energy storage material of the heat storage device is
raised above a predetermined maximum operating temperature so the
amount of the flow that passes through the heat storage device is
reduced or eliminated.
20. A process comprising the steps of: i) passing the flow of a
fluid through the heat storage device and then through the emission
reduction device using a fan or blower, so that the temperature of
the emission reduction device is increased; and then ii) cold
starting an emission source in fluid connection with the system of
claim 2.
Description
CLAIM OF PRIORITY
[0001] The present application claims the benefit of U.S.
Provisional Patent Application No. 61/440,541 (filed on Feb. 8,
2011) and PCT Patent Application No. PCT/US12/23935 (filed on Feb.
6, 2012) which are both incorporated by reference in their entirety
for all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates to systems and methods for
treating emissions from a combustion reaction so that the quantity
of one or more of the substances in the emissions is reduced when
the emissions pass through an emissions reduction device, such as a
catalytic converter. The present invention is particularly useful
when the combustion reaction has been stopped or reduced for a
period of time.
BACKGROUND OF THE INVENTION
[0003] Industry in general has been actively seeking a novel
approach to reduce and/or eliminate harmful emissions (e.g., gases
and/or particulate matter that can harm the environment, humans, or
both) from combustion reactions. For example, many vehicles that
employ an internal combustion engine employ an emission reduction
device, such as a catalytic converter, for reducing and/or
eliminating one or more harmful emissions. Whether employed in an
internal combustion engine or otherwise, many of these emission
reduction devices are ineffective or less effective at low
temperatures. When starting a combustion process, there may be a
delay, or warm-up period, between the time that the emissions begin
to pass through the emission reduction device and the time that the
emission reduction device has attained a temperature in which it
can effectively reduce the emissions as intended. During the
warm-up period, there will be increased harmful emissions. Thus, it
is beneficial to reduce (i.e., shorten) or even eliminate the
duration of the warm-up period.
[0004] There have been various approaches for reducing the
emissions during the warm-up of the emission reduction device.
Examples of devices, systems, and methods for reducing harmful
emissions during a warm-up period are given in PCT Application
Publication No. WO 2010/015940 (by Toi et al. and published on Feb.
11, 2010), German Patent Application Publication No. DE
102008040451 A1 (by Schulz et al. published on Jan. 21, 2010),
Japan Patent Application No. JP2010-001779A (by Koichi et al. and
published on Jan. 7, 2010), Japan Patent Application Publication
Number JP2008-291777A (by Hideo et al. and published on Dec. 4,
2008), and Gerd Gaiser and Patrick Mucha, "A New Design Concept for
Metallic Diesel Particulate Filter Substrates", SAE International
World Congress 2007, Paper Number 2007-01-0655, Published Apr. 16,
2007 (DOI: 10.4271/2007-01-0655), each of which is incorporated
herein by reference in its entirety. Some approaches have focused
on reducing the warm-up time by transferring more of the heat from
the combustion emissions to an emission reduction device using a
loop heat pipe, or by adding a phase change material to an emission
reduction device, or by employing a heat transfer fluid to transfer
heat from a heat storage device to an emission reduction device.
Other approaches require an additional emission reduction device
that does not require a warm-up time.
[0005] These approaches all require one or more of the following:
one or more additional fluid loops, an additional emission
reduction device, or an emission reduction device that contains a
phase change material. The addition of a phase change material to
an emission reduction device may limit the use of the emission
reduction device to reduce the risk of overheating the phase change
material. The addition of a phase change material to an emission
reduction device may increase the warm-up time of the emission
reduction device when the combustion reaction is inactive for a
sufficiently long time that the phase material loses most of its
stored heat to the environment. The addition of an additional fluid
loop and/or an additional emission reduction device may result in
increased weight and cost. For these reasons, there continues to be
a need for additional systems, devices and approaches for reducing
the emissions from a warm-up period. For example, there is a need
for an emission reduction system that offers more flexibility in
thermal management by directing the available heat to the most
beneficial recipient (e.g., at different moments in time), an
emission reduction systems employing less catalyst (such as a
system that includes a heat storage device that is substantially
free of, or even entirely free of an emission reduction catalyst),
an emission reduction system that is capable of operating in
different modes (such as an operating mode that includes flowing a
fluid through a heat storage device and later through an emission
reduction device, an operating mode that includes flowing a fluid
through an emission reduction device and later through a heat
storage device, an operating mode that includes flow of a fluid
through an emission reduction device and by-passing a heat storage
device, an operating mode that includes circulating a fluid through
a closed loop that includes the heat storage device and the
emission reduction device, or any combination thereof).
SUMMARY OF THE INVENTION
[0006] One aspect of the invention is a process for reducing the
amount of one or more undesirable substances (e.g., chemicals,
particles, or both) in a flow of a fluid from the discharge of an
emission source, wherein the process includes a step of charging a
heat storage device by flowing at least a portion of a fluid
through a fluid passage of an emission reduction device and later
through a fluid passage of the heat storage device, and a
subsequent step of warming-up the emission reduction device by
flowing a fluid through the fluid passage of the heat storage
device and later through the fluid passage of the-emission
reduction device.
[0007] Another aspect of the invention is a system for reducing the
amount of one or more undesirable chemicals in a flow of a fluid
from the discharge of an emission source, the system comprising an
emission reduction device capable of reducing a quantity of the
undesirable chemicals; a heat storage device including a thermal
energy storage material; one or more valves for controlling the
flow of the fluid; and one or more exit points; wherein the system
includes a sufficient number of valves which are positioned with
respect to the emission reduction device, the heat storage device,
and the exit, so that the system is capable of operating in at
least two modes including a warm-up mode and a charging mode.
During the warm-up mode, the emission reduction device, the heat
storage device, and at least one of the valves are in fluid
communication with each other and at least some of the flow of the
fluid passes through the heat storage device prior to passing
through the emission reduction device, wherein thermal energy is
removed from the heat storage device. During the charging mode, the
emission source, the emission reduction device, the heat storage
device, at least one exit point, and at least one valve are in
fluid communication with each other; and the heat storage device
receives heat from the flow of the fluid from the discharge of the
emission source.
[0008] Another aspect of the invention is a system for reducing the
amount of one or more undesirable chemicals in a flow of a fluid
from the discharge of an emission source, the system comprising an
emission reduction device capable of reducing a quantity of the
undesirable chemicals; a heat storage device including a thermal
energy storage material; one or more valves for controlling the
flow of the fluid; and one or more exit points; wherein the system
is capable of operating in at least two modes including:
[0009] i) a warm-up mode, wherein the emission reduction device,
the heat storage device, and at least one of the one or more valves
are in fluid communication with each other and at least some of the
flow of the fluid passes through the heat storage device prior to
passing through the emission reduction device, (e.g., wherein the
temperature of the emission reduction device is increased at least
partially from heat from the heat storage device and carried by the
fluid), wherein the temperature of the thermal energy storage
material is decreased, at least some of the thermal energy storage
material undergoes a liquid to solid phase transition, or both; and
[0010] ii) a charging mode wherein the emission reduction device,
the heat storage device, at least one of the one or more exit
points, and at least one of the one or more valves are in fluid
communication with each other, and the temperature of the thermal
energy storage material is increased, at least some of the thermal
energy storage material undergoes a solid to liquid phase
transition, or both, wherein a first portion of the flow of the
fluid passes through the heat storage device prior to passing
through the emission reduction device, (e.g., and is discharged
from the one or more exit points), wherein the amount of the one or
more undesirable chemicals in the first portion is first reduced in
the emission reduction device, and a second portion of the flow of
the fluid passes through the emission reduction device without
passing through the heat storage device.
[0011] Another aspect of the invention is a process for reducing
the emissions from an emission fluid using a heat storage device,
such as a heat storage device according to the teaching herein.
[0012] Another aspect of the invention is a process employing a
emission reduction system according to the teachings herein. The
process may include a charging mode, a warm-up mode. a by-pass
mode, or any combination thereof.
[0013] The systems and process of the present invention
advantageously may be employed for reducing emissions of carbon
monoxide, emissions of hydrocarbons, emissions of nitrogen oxides,
particulate matter or any combination thereof. The systems and
process of the present invention may be employed for reducing
emissions using reduced quantities of catalyst (e.g., the heat
storage device may be substantially free of, or even entirely free
of catalyst).
BRIEF DESCRIPTION OF THE FIGURES
[0014] The present invention is further described in the detailed
description which follows, in reference to the noted plurality of
drawings by way of non-limiting examples of embodiments of the
present invention, in which like reference numerals represent
similar parts throughout the several views of the drawings, and
wherein:
[0015] FIG. 1 is a drawing illustrating features of an emission
reduction system according to the teachings herein including one or
more valves 22 for controlling the flow of a fluid.
[0016] FIG. 2 is a drawing illustrating features of an emission
reduction system including a bleed pipe for flowing a fluid through
towards a heat storage device 12.
[0017] FIG. 3 is a flow diagram illustrating features of a by-pass
process mode 40 for by-passing a heat storage device.
[0018] FIGS. 4A, 4B, and 4C are flow diagrams illustrating features
of a charging process mode 42 for heating a heat storage device 12
with heat from an emission fluid.
[0019] FIGS. 5A and 5B are flow diagrams illustrating features of a
warm-up process mode for heating an emission reduction device 14
with heat stored in a heat storage device 12.
[0020] FIG. 6A is a drawing illustrating features of a charging
process mode for operating a system including a heat storage device
12 and an emission reduction device having a generally serial
arrangement. FIG. 6B is a drawing illustrating features of by-pass
process mode for operating the system. FIGS. 6C and 6D are drawings
illustrating features of warm-up process modes for operating the
system.
[0021] FIGS. 7A, 7B, and 7C are drawings illustrating features of
modes for operating. a system including a by-pass valve in a
warm-up process mode, a charging process-mode, and a by-pass
process mode, respectively.
[0022] FIGS. 8A, 8B, 8C, 8D, and 8E are drawings illustrating
features of a system including a heat storage device 12 and an
emission reduction device 14 having a generally parallel
arrangement. FIGS. 8A, 8B, and 8C illustrate features of various
warm-up process modes for operating a system. FIG. 8D illustrates
features of a charging process mode of operating a system. FIG. 8E
illustrates features of a by-pass mode of operating a system.
[0023] FIG. 9A is a drawing illustrating features of an article
including a thermal energy storage material that may be employed in
a heat storage device 12.
[0024] FIG. 9B is a drawing illustrating features of an article
including a thermal energy storage material that may be employed in
a heat storage device 12.
[0025] FIG. 10 is a drawing illustrating features of a heat storage
device 12 that may be employed in an emission reduction system.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0026] In the following detailed description, the specific
embodiments of the present invention are described in connection
with its preferred embodiments. However, to the extent that the
following description is specific to a particular embodiment or a
particular use of the present techniques, it is intended to be
illustrative only and merely provides a concise description of the
exemplary embodiments. Accordingly, the invention is not limited to
the specific embodiments described below, but rather; the invention
includes all alternatives, modifications, and equivalents falling
within the true scope of the appended claims.
[0027] As will be seen from the teachings herein, the present
invention provides articles, devices, systems, and process for
storing thermal energy, preferably from a combustion reaction, into
a heat storage device, and then providing at least some of the
stored heat to an emission reduction device. Heat is preferably
provided from the heat storage device to the emission reduction
device prior to or during a warm-up period so that the duration of
the warm-up period is reduced (i.e., shortened) or eliminated. The
emission reduction systems according to the teachings herein are
capable of being in fluid communication with an emission fluid from
an emission source and may be advantageously employed to reduce the
amount of one or more undesirable substances (such as a chemicals,
a particle, or both) from the emission fluid.
[0028] The system generally includes one or more emission reduction
devices, one or more heat storage devices, one and one or more exit
points. The emission reduction systems preferably includes one or
more valves that allow the system to operate in different modes.
The emission reduction system may be capable of operating in one or
any combination (e.g., two or more) of the following modes: a
warm-up mode in which heat from a heat storage device is
transferred to an emission reduction device; a charging mode in
which heat from a fluid emission is transferred to a heat storage
device; or a by-pass mode in which some or all of a fluid emission
by-passes a heat storage device and flows through an emission
reduction device.
[0029] The warm-up mode may advantageously be employed to increase
the temperature of the emission reduction device so that the
emission reduction device is more effective in reducing the amount
of one or more undesirable chemicals in the emission fluid. During
the warm-up mode, the temperature of the heat storage device may
decrease (e.g., the temperature of the thermal energy storage
material in the heat storage device may decrease). Preferably,
during the warm-up mode, a portion of, or even all of the thermal
energy storage material (TESM) in the heat storage device undergoes
a liquid to solid phase transition.
[0030] The charging mode may advantageously be employed for
transferring heat from an emission fluid to the heat storage device
so that the heat can be stored in the heat storage device. During
the charging mode, the temperature of the TESM in the heat storage
device may be increased, some or all of the TESM may undergo a
solid to liquid phase transition, or both. Preferably, during the
charging mode, the concentration of TESM that is a liquid is
increased. During the charging mode, it may be desirable for the
emission fluid to pass through an emission reduction device prior
to passing through the heat storage device so that the emission
fluid has a sufficiently high temperature to enable the reduction
of one or more undesirable chemicals as it passes through the
emission reduction device.
[0031] The by-pass mode may advantageously be employed when the
temperature of the TESM reaches an upper limit temperature so that
the heat storage device and/or the TESM is not overheated. In
particular, it has been determined that heating of the TESM above
the upper temperature limit, such as by cycling for 1000 or more
cycles, may result in a reduction of the heat storage capacity of
the heat storage device. During the by-pass mode, the flow of the
emission fluid through the heat storage device may be reduced or
eliminated. By way of example, during the by-pass mode, the flow of
the emission fluid through the heat storage device may be
controlled using one or more valves for maintaining the temperature
of the heat storage device and/or the TESM within a predetermined
range, such as between a first temperature equal to or above a
solid to liquid phase transition temperature of the TESM and a
second higher temperature that is at or below the upper temperature
limit of the TESM. As such, the by-pass mode may be employed for
maintaining the TESM in a liquid state, for avoiding overheating
the TESM, or both.
[0032] The fluid emission source may be any emission source, such
as an emission source that results in the flow of a fluid
containing one or more undesirable chemicals. The one or more
undesirable chemicals may include one or more chemicals that are
provided to the emission source (e.g., one or more reactants), one
or more reaction products, or any combination thereof. The emission
source may be from the flow of a fluid resulting from a combustion
reaction. Without limitation, exemplary emission sources that may.
employ a combustion reaction include an oil heater, a natural gas
heater, a gas turbine, a boiler, an incinerator, or an internal
combustion engine. The emission source may be stationary (such as
in a home, building, factory, power plant, and the like), or it may
be mobile. Emission sources that are mobile include emission
sources on a means of transport such as a vehicle, a plane, a
trains, a watercraft, and the like. The emission source may react
one or more hydrocarbon reactants to produce energy, preferably by
a combustion reaction with oxygen. Any hydrocarbon reactant may be
employed. The hydrocarbon reactant may be a solid, a liquid, a gas,
or any combination thereof. The hydrocarbon reactant may be a
fossil fuel, such as oil, natural gas, coal, gasoline, diesel fuel,
and the like. Particularly preferred fossil fuels include fossil
fuels that have been refined, such as diesel fuel and gasoline.
Another particularly preferred fossil fuel is natural gas. The
hydrocarbon reactant may be a bio-fuel, derived from One or more
biological organisms, such as from plants, algae, animals, or any
combination thereof. Other hydrocarbon reactants that may be used
include synthetic fuels, such as synthetic fuels derived from
organic or inorganic reagents.
[0033] As described hereinbefore, the emission reduction device may
be employed to reduce the amount of one or more undesirable
substances, such as one or more undesirable chemicals, undesirable
particulate matter, or both. As used herein, an. undesirable
chemical may be any chemical other than water, nitrogen gas, and
oxygen. For example, an undesirable chemical may be any chemical
other than water, nitrogen gas, oxygen, and carbon dioxide. The
undesirable chemicals may be chemical that are by-products from the
emission source or entrained in the emission fluid. The undesirable
chemicals may be chemicals that are toxic or pose other health
risks, chemicals that pose a threat to the environment, or both.
Without limitation, the one or more undesirable chemicals may
include, consist essentially of, or consist entirely of
hydrocarbons, carbon monoxide, nitrogen oxide, carbon containing
particles (e.g., soot particles), or any combination thereof.
[0034] The heat storage device may be any device capable of storing
heat so that the heat may be used to heat an emission reduction
device, such as when the emission reduction device has a
temperature below the lower limit operating temperature of the
emission reduction device. The heat storage device may include one
or more TESMs. The amount of TESM in the heat storage device may be
such that the heat storage device is capable of storing a
sufficient amount of heat to increase the temperature of the
emission reduction device from an ambient temperature to a
temperature above its lower limit operating temperature, or
sufficiently close to the lower limit operating temperature. For
example, the heat storage device may be capable of storing a
sufficient amount of heat to increase the temperature of the
emission reduction device from about 0.degree. C. or less to about
110.degree. C. or more. As described hereinafter, particularly
preferred TESMs for use in the heat storage device have one or more
solid to liquid phase transitions at a temperature above the lower
limit operating temperature of the emission reduction device.
[0035] The heat storage device may include one or more orifices for
allowing the fluid from the emission source to flow into the heat
storage device and one or more orifices for allowing the fluid from
the emission source to flow out of the heat, storage device. It
will be appreciated according to the teachings herein that the heat
storage device may be used in a system that operates in a plurality
of modes including a first operating mode in which a first orifice
of the heat storage device is used for flowing at least a portion
of the fluid into the heat storage device and a second operating
mode in which the first orifice is used for flowing the fluid out
of the heat storage device. Similarly, the heat storage device may
have a second orifice for flowing at least a portion of the fluid
out of the heat storage device during the first mode, for flowing
at least a portion of the fluid into the heat storage device during
the second mode, or both. According to the teachings herein, the
heat storage device may be. employed in a system in which the first
orifice of the heat storage device allows the fluid only to flow
into the heat storage device, the second orifice of the heat
storage device allows the fluid only to flow out of the heat
storage device, or both.
[0036] The heat storage device may include one or more fluid
passages for flowing the fluid through the heat storage device. The
one or more fluid passages may provide a fluid connection between
the one or more orifices for flowing the fluid into the heat
storage device and the one or more orifices for flowing the fluid
out of the heat storage device. The one or more fluid passages may
be employed for flowing a fluid from the heat storage device to the
emission reduction device while operating the system in a warm-up
mode, Preferably, the same one or more fluid passages are also
employed for flowing some or all of the emission fluid through the
heat storage device while operating the system in-the charging
mode.
[0037] The heat storage device may include a catalyst located in
the fluid passage of the heat storage device, for instance on one
or more surfaces of the fluid passage and/or on one or more
supports in the fluid passage. If employed in the heat storage
device, the type and amount of catalyst may be selected so that the
heat storage device is capable of reducing the amount of the one or
more undesirable chemicals in the emission fluid while operating
the system in a warm-up mode (such as during a cold-start). if
employed, the catalyst in the heat storage. device may be capable
of reducing the amount of the one or more undesirable chemicals in
the fluid (e.g., when the heat storage device has a temperature at
which the undesirable chemicals undergo a reaction, such as a
temperature of about 100.degree. C. or more, about 115.degree. C.
or more, about 125.degree. C. or more, or about 150.degree. C. or
more. If employed, the catalyst in the heat storage system may be
the same as, or different from the catalyst employed in the
emission reduction device. Preferably, the heat storage device
includes a catalyst having a minimum operating temperature (e.g., a
minimum temperature at which the catalyst is effective in reducing
one or more undesirable chemicals) than the minimum operating
temperature of the catalyst in the emission reduction device.
[0038] According to the teachings herein, in embodiments of the
invention the heat storage device may be substantially or entirely
free of a catalyst for reducing the amount of the one or more
undesirable chemicals. As such, the amount of an undesirable
chemical as a fluid enters the heat storage device may be
substantially the same as the amount of the undesirable chemical as
the fluid exits the heat storage device.
[0039] A particularly preferred heat storage device for use in the
present invention is a heat storage described in paragraphs 008-117
and paragraphs 132-141 of International Patent Application No.
PCT/US11/22662 (filed by Soukhojak et al. on Jan. 27, 2011),
incorporated herein by reference. For example, the heat storage
device may include one or more articles (such as a stack of
articles) having one or any combination of the following features
(e.g., all of the following features): the articles may comprise a
capsular structure having one or more sealed spaces, the sealed
spades may encapsulate one or more TESMs; the capsular structure
may have one or more fluid passages which are sufficiently large to
allow a heat transfer fluid to flow through the one or more fluid
passages; or when a heat transfer fluid contacts the capsular
structure the TESM may be physically isolated from the heat
transfer fluid.
[0040] The heat storage device may be sufficiently insulated so
that the heat storage device, when heated to about 300.degree. C.,
and exposed to an ambient temperature of about 0.degree. C.,
decreases in temperature at a generally low rate, such as a rate of
about 1.degree. C./min or less, about 0.2.degree. C./min or less,
about 0.1.degree. C. or less, or about 0.05.degree. C. or less.
When the heat storage device is heated to about 300.degree. C. and
then exposed to an ambient temperature of about 25.degree. C., it
may be sufficient insulated so that a temperature of at least about
100.degree. C. is maintained in the heat storage device (e.g.,
without flow of a fluid through the device) for about 2 hours or
more, preferably about 4 hours or more, more preferably about 10
hours or more, and most preferably about 24 hours or more.
Preferably the heat storage device is substantially thermally
isolated when fluid is not flowing through the fluid passages. For
example, when the fluid is not flowing through the heat storage
device, the system may be free of a thermal conduction path between
the TESM in the heat storage device and the emission reduction
device.
[0041] For example, the TESM may be encapsulated between two metal
layers that are sealingly attached to form one or more isolated
capsules, Without limitation, the heat storage device may employ a
capsule or an arrangement of capsules (e.g., a blister pack or
stack of blister packs) described in U.S. Patent Application
Publication No. US 2009/0250189 A1, published on Oct. 8, 2009,
incorporated herein by reference,
[0042] The heat storage device preferably has a sufficient amount
of thermal energy so that the heat storage device can release to a
fluid (e.g., to an emission fluid) about 0.02 MJ or more of heat,
preferably about 0.08 MJ or more of heat, and more preferably about
0.14 MJ or more of heat, and most preferably about 0.20 MJ or more
of heat when the heat storage device is cooled from about
300.degree. to about 80.degree. C.
[0043] Without limitation, suitable TESMs for the heat storage
device include materials that are capable of exhibiting a
relatively high density of thermal energy as sensible heat, latent
heat, or preferably both. The TESM is preferably compatible with
the operating temperature range of the heat storage device. For
example the TESM is preferably a solid at the lower operating
temperature of the heat storage device, is at least partially a
liquid (e.g., entirely a liquid) at the maximum operating
temperature of the heat storage device, does not significantly
degrade or decompose at the maximum operating temperature of the
device, or any combination thereof. The TESM preferably does not
significantly degrade or decompose when heated to the maximum
operating temperature of the device for about 1,000 hours or more,
or even for about 10,000 hours or more.
[0044] The TESM may be a phase change material having a solid to
liquid transition temperature. The solid to liquid transition
temperature of the TESM may be a liquidus temperature, a melting
temperature, or a eutectic temperature. The solid to liquid
transition temperature should be sufficiently high so that when the
TESM is at least partially or even substantially entirely in a
liquid state enough energy is stored to heat the emission reduction
device. The solid to liquid transition temperature should be
sufficiently low so that the heat transfer fluid, the one or more
objects to be heated, or both, are not heated to a temperature at
which it may degrade. As such the desired temperature of the solid
to liquid transition temperature may depend on the object to be
heated and the method of transferring the heat. For example, in an
application that transfers the stored heat to an engine (e.g., an
internal combustion engine) using a glycol/water heat transfer
fluid, the maximum solid to liquid transition temperature may be
the temperature at which the heat transfer fluid degrades. As
another example, the stored heat may be transferred to an
electrochemical cell of a battery using a heat transfer fluid where
the heat transfer fluid has a high degradation temperature, and the
maximum solid to liquid temperature may be determined by the
temperature at which the electrochemical cell degrades or otherwise
fails. The solid to liquid transition temperature may be any
temperature above ambient (or above 40.degree.) which is suitable
for the system which the TESMs are utilized. Preferably, the solid
to liquid transition temperature is greater than about 100.degree.
C., more preferably greater than about 120.degree. C., more
preferably greater than about 150.degree. C., even more preferably
greater than about 180.degree. C., and most preferably greater than
about 190.degree. C. The TESM may have a solid to liquid transition
temperature less than about 400.degree. C., preferably less than
about 350.degree. C., more preferably less than about 290.degree.
C., even more preferably less than about 250.degree. C., and most
preferably less than about 200.degree. C. It will be appreciated
that depending on the application, the solid to liquid transition
temperature may be from about 80.degree. C. to about 150.degree.
C,, from about 125.degree. C. to about 250.degree. C. from about
100.degree. C. to about 200.degree. C. from about 150.degree. C. to
about 250.degree. C., from about 175.degree. C. to about
400.degree. C., from about 200.degree. C. to about 375.degree. C.,
from about 225.degree. C. to about 400.degree. C., or from about
200.degree. C. to about 300.degree. C.
[0045] For some applications, such as transportation related
applications, it may desirable for the thermal energy material to
efficiently store energy in a small space. As such, the TESM may
have a high heat of fusion density (expressed in units of
megajoules per liter), defined by the product of the heat of fusion
(expressed in megajoules per kilogram) and the density (measured at
about 25.degree. C. and expressed in units of kilograms per liter),
The TESM may have a heat of fusion density greater than about 0.1
MJ/liter, preferably greater than about 0.2 MJ/liter, more
preferably greater than about 0.4 Mj/liter, and most preferably
greater than about 0.6 MJ/liter. Typically, the TESM has a heat of
fusion density less than about 5 MJ/liter. However, TESMs having a
higher heat of fusion density may also be employed.
[0046] For some applications, such as transportation related
applications, it may be desirable for the. TESM to be light weight.
For example, the TESM may have a density (measured at about
25.degree. C.) less than about 5 g/cm3, preferably less than about
4 g/cm3, more preferably less than about 3.5 g/cm3, and most
preferably less than about 3 g/cm3. The lower limit on density is
practicality. The TESM may have a density (measured at about
25.degree. C.) greater than about 0.6 g/cm3, preferably greater
than about 1.2 g/cm3 and more preferably greater than about 1.7
g/cm3.
[0047] The sealed spaces may contain any art known TESM. Examples
of TESMs that may be employed in the thermal heat storage device
include the materials described in Atul Sharma, V. V. Tyagi, C. R.
Chen, D. Buddhi, "Review on thermal energy storage with phase
change materials and applications", Renewable and Sustainable
Energy Reviews 13 (2009) 318-345, and in Belen Zalba, Jose Ma Mann,
Luisa F. Cabeza, Harald Mehling, "Review on thermal energy storage
with phase change: materials, heat transfer analysis and
applications", Applied Thermal Engineering 23 (2003) 251-283, both
incorporated herein by reference in their entirety. Other examples
of suitable TESMs that may be employed in the heat transfer device
include the TESMs described in U.S. Patent Application Publication
Nos. US 200910250189 A1 (published on Oct. 8, 2009) and US
2009/0211726 A1 (published on Aug. 27, 2009), both incorporated
herein by reference.
[0048] The TESM may include (or may even consist essentially of or
consist of) at least one first metal containing material, and more
preferably a combination of the at least one first metal containing
material and at least one second metal containing material. The
first metal containing material, the second metal containing
material, or both, may be a substantially pure metal, an alloy such
as one including a substantially pure metal and one or more
additional alloying ingredients (e.g., one or more other metals),
an intermetallic, a metal compound (e.g., a salt, an oxide or
otherwise), or any combination thereof. One preferred approach is
to employ one or more metal containing materials as part of a metal
compound; a more preferred approach is to employ a mixture of at
least two metal compounds. By way of example, a suitable metal
compound may be selected from oxides, hydroxides, compounds
including nitrogen and oxygen (e.g., nitrates, nitrites or both),
halides, or any combination thereof. It is possible that ternary,
quaternary or other multiple component material systems may be
employed also. The TESMs herein may be mixtures of two or more
materials that exhibit a eutectic.
[0049] The TESM may include lithium cations, potassium cations,
sodium cations, or any combination thereof. The TESM may include
lithium cations at a concentration from about 20% to about 80 mole
%, preferably from about 30% to about 70% based on the total moles
of cations in the TESM. The TESM may include lithium nitrate at a
concentration from about 20 mole % to about 80 mole % lithium
nitrate, based on the total moles of salt in the TESM. The TESM may
includes from about 30 mole % to about 70 mole % lithium nitrate
and from about 30 mole % to about 70 mole % sodium nitrate. The
TESM may include lithium nitrate and sodium nitrate at a total
concentration greater than 90 wt. % (e.g., greater than about 95
wt. %) based on the total weight of the TESM. The TESM may include
at least one first metal compound that includes a nitrate ion, a
nitrite ion, or both; at least one second metal containing material
including at least one second metal compound; and optionally
including water, wherein the water concentration if any is present
is less than about 10 wt %. The TESM may be a eutectic composition
including lithium nitrate, sodium nitrate, lithium nitrite, sodium
nitrite, or any combination thereof.
[0050] The emission reduction device may be capable of reducing the
amount of at least one or more of the harmful chemicals in a fluid
that passes through the emission reduction device. Preferably, the
emission reduction device is capable of reducing the amount of
nitrogen oxides, hydrocarbons, carbon monoxide, particulate matter,
or any combination thereof. More preferably, the emission reduction
device is capable of reducing the amount of nitrogen oxides,
hydrocarbon, carbon monoxide, or any combination thereof. Even more
preferably, the emission reduction device is capable of reducing
the amount of carbon monoxide and the amount of hydrocarbons in a
fluid that passes through the emission reduction device. Most
preferably, the emission reduction device is capable of reducing
the amount of carbon monoxide, the amount of hydrocarbons, and the
amount of nitrogen oxides in a fluid that passes through the
emission reduction device. The emission reduction device may be
capable of reacting (e.g., catalytically reacting) nitrogen oxides,
such as to form nitrogen gas, oxygen gas, or preferably both. The
emission reduction device may be capable of reacting (e.g.,
catalytically reacting) a hydrocarbon in a combustion reaction
(i.e., a reaction with oxygen) that produces, at least carbon
dioxide and water. The emission reduction device may be capable of
reacting (e.g., catalytically reacting) carbon monoxide, such as in
a reaction that produces at least carbon dioxide.
[0051] The emission reduction device may include one or more
orifices for flowing the fluid into the device and one or more
orifices for flowing the fluid out of the device. The emission
reduction device may include one or more passages containing a
catalyst capable of catalytically reacting with one or more harmful
chemicals. The emission reduction device may include one or more
catalyst supports for supporting the catalyst, such as a catalyst
support that is porous, ceramic, or both. Exemplary catalysts and
catalyst supports which may be employed include those described in
U.S. Pat. No. 6,953,544 B2 column 2, line 59 to column 8, line 9,
incorporated herein by reference. The catalyst may include a noble
metal, a base metal, or any combination thereof.
[0052] The catalyst may be any suitable catalyst, such as those
known in the art. In particular, the catalyst may be any one of the
following preferred embodiments or combinations of them.
[0053] A first preferred catalyst is directly bound-metal
catalysts, such as noble metals, base metals and combinations
thereof. Examples of noble metal catalysts include platinum,
rhodium, palladium, ruthenium, rhenium, silver and alloys thereof.
Examples of base metal catalysts include copper, chromium, iron,
cobalt, nickel, zinc, manganese, vanadium, titanium, scandium and
combinations'thereof. The metal catalyst, preferably, is in the
form of a metal, but may be present as an inorganic compound, such
as an oxide, nitride and carbide, or as a defect structure within
the ceramic grains of the porous catalyst support. The metal may be
applied by any suitable technique, such as those known in the art.
For example, the metal catalyst may be applied by chemical vapor
deposition.
[0054] A second preferred catalyst coating is one that is
incorporated into the lattice structure of the ceramic grains of a
porous catalyst support. For example, an element may be cerium,
zirconium, lanthanum, magnesium, calcium, a metal element described
in the previous paragraph or combinations thereof. These elements
may be incorporated in any suitable manner, such as those known in
the art and by methods described later.
[0055] A third preferred catalyst is a combination of ceramic
particles having metal deposited thereon. These are typically
referred to as wash coats. Generally, wash coats consist of
micrometer sized ceramic particles, such as zeolite,
aluminosilicate, silica, ceria, zirconia, barium oxide, barium
carbonate and alumina particles that have metal deposited thereon.
The metal may be any previously described for directly deposited
metal. A particularly preferred wash coat catalyst coating is one
comprised of alumina particles having a noble metal thereon. It is
understood that the wash coat may be comprised of more than one
metal oxide, such as alumina having, oxides of at least one of
zirconium, barium, lanthanum, magnesium and cerium.
[0056] A fourth preferred catalyst is a perovskite-type catalyst
comprising a metal oxide composition, such as those described by
Golden in U.S. Pat. No. 5,939,354.
[0057] A fifth preferred catalyst is one that is formed by and
deposited on the catalyst support by calcining at a temperature of
from about 300.degree. C. to about 3000.degree. C., a composition
that comprises (a) an aqueous salt, solution containing at least
one metal salt and (b) an amphiphilic ethylene oxide containing
copolymer, wherein the copolymer has an average molecular weight of
greater than 400, an ethylene oxide content of 5 to 90 percent and
an HLB of between -15 and 15, as described by Gruenbauer, et al.,
PCT patent application Ser. No. 99/18809. In addition, the catalyst
may also be one such as described by U.S. Pat. No. 5,698,483 and
PCT patent application Ser. No. 99/03627.
[0058] More preferred catalysts include one or more atoms selected
from the group consisting of platinum, palladium, rhodium, cerium,
iron, manganese, nickel, copper, and any combination thereof. Most
preferred catalysts include, consist essentially of, or consist
entirely of platinum, palladium, rhodium, or any combination
thereof.
[0059] The emission reduction system (e.g., the emission reduction
device) may include one or more art known diesel particulate
filters. For example, the emission reduction system or the emission
reduction device may include a diesel particulate filter described
in Patent Application Publication Nos. US 2008/0017573,
2008/0148700, and 2010/0003172, incorporated herein by reference in
their entirety. Preferred diesel particulate filters are ceramic.
Preferred diesel particulate filters are honeycomb structured. The
filter may comprise silicon carbide, cordierite, an acicular
mullite. The filter may optionally contain one or more
catalysts.
[0060] Particularly preferred emission reduction devices include
catalytic converters or scrubbers.
[0061] The one or more passages of the emission reduction device
preferably is employed for passing an emission fluid through the
emission reduction device while operating the system in a by-pass
mode, while operating the system in a charging mode, or both. The
same one or more passages of the emission reduction device
preferably is employed while operating the system in a warm-up mode
for heating the emission reduction device using a fluid (which
according to the teachings herein may be an emission fluid or a
different fluid).
[0062] The system may have one or more additional components such
as one or more valves, one or more fans or blowers, one or more
exit points, one or more mufflers, one or more controllers, one or
more devices or components for measuring temperature (e.g., at one
or more locations in a system according to the teachings herein),
one or more devices or components for measuring fluid flow rate
(e.g., at one or more locations in a system according to the
teachings herein), one or more devices or components for measuring
fluid pressure (e.g., at one or more locations in a system
according to the teachings herein), or any combination thereof. For
example, the system may include one or more thermocouples or other
means of measuring a temperature of a component selected from the
group consisting of a heat storage device, a fluid (such as an
emission fluid), an emission reduction device, and any combination
thereof.
[0063] The system may include one or more connectors for providing
a fluid communication between two components of the system.
Suitable connectors have two or more openings and a passageway
between the two openings for flowing a fluid between the two
openings. Preferred connectors have solid surfaces except for the
openings, have exactly two openings. Most preferred connectors have
solid surfaces except for the openings and have exactly two
openings for the passageway. A connector may be used for connecting
two or more components. For example, a connector may connect two or
more of the components selected from an emission source, a heat
storage device, an emission reduction device, a valve, an exit
point, a blower or fan, or a muffler. When in use, a connector
between two components may be used to flow a portion of, the
majority of, or the entirety of a fluid from a first component to a
second component. It will be appreciated that a connector may be of
any form or shape and may have subcomponents, including
subcomponents which may also be suitable as connectors, A preferred
connector includes, or consists essentially of a pipe or tube.
[0064] The system may include one or more valves for controlling
the flow of the fluid (e.g., the emissions fluid) between two or
more of the following components, an emissions source, a heat
storage device, an emissions reduction device, an exit point, a
muffler, or any combination thereof. According to the teachings
herein, the system may advantageously include one or more valves
capable of changing the order in which the fluid flows through two
or more components. For example, the one or more valves may be
capable of changing the order in which the fluid flows through the
heat storage device and the emission reduction device. In
particular, the one or more valves may provide a first
configuration in which the fluid flows through the heat storage
device prior to flowing through the emission reduction device and a
second configuration in which the fluid flows through the emission
reduction device prior to flowing through the heat storage
device.
[0065] The system should have a sufficient number of valves so that
the system can operate in a plurality of modes. For example, the
system may be capable of operating in two or more, or three or more
modes with the selection of the valves. The selection of the valves
includes the number of valves, the positioning of the valves (e.g.,
with respect to the other components), the type of valves, and the
like. Preferably, the system has a sufficient number of valves so
that the system can operate in a warm-up mode and a charging mode,
More preferably, the system has a sufficient number of valves so
that the system is capable of operating in a warm-up mode, a
charging mode, and a by-pass mode.
[0066] The valves may have multiple positions. A valve may have
multiple discrete positions. According to the teachings herein,
valves having one or more ranges of continuously variable position
may also be employed. Each valve, independently or dependently, may
have 2 or more positions. Preferred valve have 2, 3, or 4
positions. However valves having more positions may also be used.
When the valve is moved from one position to another position, an
inlet to the valve may change, an outlet from the valve may change,
a flow path may be partially or entirely blocked, a flow path may
be partially or entirely opened, or any combination thereof.
[0067] According to the teachings herein, the system, may
advantageously include one or more valves capable of diverting the
flow of the fluid so that some or all of the flow by-passes the
heat storage device. For example, the one or more valves may
provide a configuration (e.g., set of positions or settings) in
which some or all of the fluid passes through the heat storage
device while all of the fluid passes through the emission reduction
device and a different configuration in which the fluid passes the
emission reduction device and does not pass through the heat
storage device. As another example, the one or more valves provide
a configuration in which essentially all, or all of the fluid pass
through both the heat storage device and the emission reduction
device, and the one or more valves provide a different
configuration in which at least a portion, or even all of the fluid
does not pass through the heat storage device.
[0068] The system for reducing one or more emissions may include
one or more systems or devices for flowing or circulating a fluid
between the heat storage device and the emission reduction device
to that heat from the heat storage device is provided to the
emission reduction device. For example, a system or device for
flowing or circulating a fluid between the heat storage device and
the emission reduction device may be employed when the emissions
source is not providing an emissions fluid. Examples of systems or
devices for flowing or circulating a fluid include a fan, a blower,
a vacuum, an injector and the like. The blower, fan, vacuum, or
injector may be employed while the system is operating in a warm-up
mode prior to the operation of an emission source. The blower, fan,
vacuum, or injector may be employed to increase the temperature of
the emission reduction source, preferably so that the temperature
of the emission reduction is above its lower limit operating
temperature. The system or device for flowing or circulating a
fluid may be used to flow a fluid from the passage of the heat
storage device that is used to flow the emission fluid through the
heat storage device while operating in a charging mode and to a
passage of the emission reduction device that is used to flow the
emission fluid through the emission reduction device during the
charging mode. As such, the need for any separate closed loop (such
as a permanent closed loop) and necessary heat transfer fluid for
transferring heat from the heat storage device to the emission
reduction device may advantageously be eliminated.
[0069] During the warm-up mode, one or more valves may be employed
(e.g., by setting the valve to a discrete position or by adjusting
a valve having a continuous range of settings) for creating a
closed loop path including the heat storage device having a first
temperature, the emission reduction device having a second
temperature, and the blower, fan, vacuum, or injector all in fluid
communication, wherein the blower, fan, vacuum, or injector
circulates a fluid between the heat storage device having and the
emission reduction device when the first temperature is higher than
the second temperature, when the second temperature is below the
lower limit operating temperature of the emission reduction device.
Such a warm-up mode may be used when the first temperature is above
the lower limit operating temperature of the emission reduction
device, or any combination thereof. Instead of creating a closed
loop path, the one or more valves may be employed in the warm-up
mode to allow a fan or blower to flow a fluid from a point which is
used as an exit point for the emission fluid during the charging
mode, later through the heat storage device, and later through the
emission reduction device.
[0070] The system may include one or more exit points. The exit
point may be used during one or more modes of operation to allow
the emission fluid to exit the system. For example, the exit point
may be an exhaust pipe that allows the emission fluid to enter the
environment. As such, it will be appreciated that there may be an
interest in reducing or eliminating one or more harmful chemicals
from the emission fluid prior to passing an exit point.
[0071] The system may include a controller, such as a controller
that controls the mode of operating the system, such as according
to the teachings herein. A controller may control one or more
valves so that the flow of a fluid in the system is controlled. A
controller may monitor a fluid flow rate in one or more locations
in the system. A controller may monitor a fluid pressure in one or
more locations in the system. A controller may monitor one or more
temperatures of the system, compare a temperature of the system to
a predetermined value, compare a temperature of the system to a
different temperature of the system, or any combination thereof.
For example, the controller may control the system so that a fluid
flows through the heat storage device and later through the
emission reduction device when the temperature of the emission
reduction device is below a predetermined lower temperature limit,
when the temperature of the heat storage device is greater than the
temperature of the emission reduction device, or preferably both.
The controller may control the system so that at least a portion of
a fluid flows through the emission reduction device and by-passes
the heat storage device when the temperature of the heat storage
device is greater than a predetermined upper temperature limit. The
controller may control the system so that some or all of a fluid
(such as an emission fluid) flows through the heat storage device
when the temperature of the heat storage device is below a
predetermined lower temperature limit (for example, when the fluid,
the emission reduction device, or both has a temperature greater
than the temperature of the heat storage device). The controller
may also control the operation of a fan, blower, or vacuum, such as
during a warm-up mode for heating the emission reduction device,
preferably prior to operating an emission source. The controller
may function by controlling one or more flows so that the available
heat is provided to the device or devices that can benefit from the
heat. The system may have flexibility in its thermal management,
and the controller may provide the control for this thermal
management, such as by monitoring one or more temperatures and
controlling one or more valves.
[0072] With reference to FIG. 1, the emission reduction system 10
may include one or more heat storage devices 12, one or more
emission reduction devices, e.g. 14, and one or more valves 22 that
are in thermal communication with one or more emission sources 18
and one or more exit points 20. The emission reduction system 10
may be arranged so that a single valve 22 has an inlet 21 connected
to an emission source pipe 24 that provides the emission fluid to
the system and a plurality of outlets 23, 23 connected to the
transfer pipe 26 and the by-pass pipe 28. The transfer pipe 26 may
be connected to a first orifice 11 (e.g., an inlet) of the heat
storage device 12. The by-pass pipe 28 may be connected directly or
indirectly to a second orifice 13 (e.g., an outlet) of the heat
storage device 12, a first orifice 15 (e.g., an inlet) of the
emission reduction device, or preferably both. The system may
include an exit pipe 32, such as an exit pipe connected to a second
orifice 17 (e.g., an outlet) of the emission reduction device 14 so
that the emission fluid may flow to an exit point 20. The system
may be operated in a warm-up mode (e.g., when the temperature of
the emission fluid in the emission source pipe and/or the
temperature of the emission reduction device is lower than the
temperature of the heat storage device), by setting the valve 22 to
a position so that essentially all of, or entirely all of the
emission fluid passes through the heat storage device prior to
passing through the emission reduction device (i.e., the emission
fluid flows primarily, or entirely from source pipe 24 to transfer
pipe 26). The system may be operated in a charging mode (e.g., when
the temperature of the emission fluid is greater than the
temperature of the heat storage device) by setting the valve 22 to
a position so that at least a portion of the emission fluid passes
through the heat storage device 12. The system may be operated in a
by-pass mode (e.g., when the temperature of the emission fluid is
greater than the temperature of the heat storage device and the
TESM in the heat storage device is in a liquid state) by setting
the valve 22 to a position so that at least a portion, or even all
of the of the emission fluid by-passes the heat storage device 12
by flowing from emission source pipe 24 through the valve 22, and
to the by-pass pipe 28. When operating the system in the by-pass
mode, the flow of the emission fluid through the heat storage
device is reduced relative to the flow when operating the system in
the charging mode.
[0073] The emission reduction system may include one or any
combination of the features illustrated in FIG. 2. The system may
include a bleed pipe 19 that permits a flow of a portion of the
emission fluid through the heat storage device 12. For example, the
bleed pipe 19 may allow a portion of the emission fluid to flow
through the heat storage device 12 even when a valve is set to only
allow a connection between the source pipe 24 and the by-pass pipe
28. The amount of the emission fluid that flows through the bleed
pipe 19 may be sufficient to substantially maintain the temperature
of the heat storage device 12 when the TESM is in a liquid state.
The amount of the emission fluid that flows through the bleed pipe
19 preferably is sufficiently low so that the heat storage device
12 is not overheated (e.g., so that the TESM does not degrade).
[0074] The emission reduction system may be capable in operating in
a by-pass mode, such as the by-pass mode illustrated in FIG. 3. The
by-pass mode 40 may be characterized by a process including a step
of flowing at least a portion of, or even all of the emission fluid
from an emission source 34 through the emission reduction device 14
to an exhaust point 36 without passing through the heat storage
device 12. For example, substantially all of the emission fluid may
by-pass the heat storage device 12.
[0075] The emission reduction system may be capable of operating in
a charging mode, such as the charging modes illustrated in FIGS.
4A, 4B, and 4C. The charging mode 42 may be characterized by a
process including a step of flowing at least a portion of, or even
all of the emission fluid from an emission source 34 through the
emission reduction device 14 and through the heat storage device 12
prior to flowing through an exhaust point 36. For example, during
the charging mode, the system may include a process including a
step of flowing at least a portion, or even all of the emission
fluid through the emission reduction device 14 prior to flowing
through heat storage device 12, such as illustrated in FIG. 4A.
Alternatively, during the charging mode, the system may include a
process including a step of flowing at least a portion, or even all
of the emission fluid through the heat storage device 12 prior to
flowing through the emission reduction device 14, such as
illustrated in FIG. 4B. While operating the system in, the charging
mode, a portion of the emission fluid may by-pass the heat storage
device 12, such as illustrated in FIG. 4C. It will be appreciated,
that during the charging mode, a sufficient portion of the emission
fluid flows through the heat storage device 12, so that the
temperature of the TESM is increase, so that the TESM undergoes a
solid to liquid phase transition, or both.
[0076] The emission reduction system may be capable in operating in
a warm-up mode, such as the warm-up mode illustrated in FIG. 5A and
56. The warm-up mode may operate when the temperature of the heat
storage device 12 is greater than the temperature of the emission
fluid, greater than the temperature of the emission reduction
device 14, or both. The warm-up mode may be employed when
cold-starting an emission source, such as following a period during
which the emission source been idled or turned off. The warm-up
mode 44 may be characterized by a process including a step of
flowing at least a portion of, or even all of the emission fluid
from an emission source 34 through the heat storage device 12 prior
to flowing through the emission reduction device 14, such as
illustrated in FIG. 5A. While operating the system in the warm-up
mode, preferably all of the emission fluid flows through the heat
storage device 12 prior to flowing through the emission reduction
device. The warm-up mode may operate as a loop, such as illustrated
in FIG. 5B, where a fluid is circulated in a loop for transferring
heat from the heat storage device to the emission reduction device.
At a later time, a portion of the loop may be used for a charging
mode.
[0077] The emission reduction system may include one or more valves
arranged so that the system is capable of being operated in a first
mode for flowing a fluid through the heat storage device 12 prior
to flowing through the emission reduction device 14 and is capable
of being operated in a second mode for flowing at least a portion
of the fluid through the emission reduction device 14 and
by-passing the heat storage device 12, such as the system
illustrated in FIGS. 6A, 6B, 6C, and 6D. The heat storage device 12
and the emission reduction device 14 may be arranged in a generally
serial arrangement. The system may include a sufficient number of
valves so that the system is capable of operating in the different
modes. For example, the system may include three or more valves, as
illustrated in FIGS. 6A, 6B, 6C, and 6D. It will be appreciated
that a valve, may be replaced with one or more additional valves to
control the flow of a fluid. The system may be operated in a
charging mode when an emission fluid has a temperature greater than
the temperature of the heat storage device, such as illustrated in
FIG. 6A. As illustrated in FIG. 6A, during the charging mode, the
system may include a first set of components and/or portions of
components 41 that are in fluid communication and have the fluid
flowing through it. As illustrated in FIG. 6A, during the charging
mode, the system may include a second set of components and/or
portions of components, 43 without the fluid flowing through it.
For example, the system may include a valve 22 having a first flow
path including an entrance and an exit that is part of the first
set 41 and one or more flow paths (e.g., each including an opening
and an exit) that is part of the second set 43. During the various
modes of operation, the first set of components and/or portions of
components 41 employed in flowing the fluid may include more
components and/or portions of components, the same components
and/or portions of components (e.g., employed in different
sequences), or fewer components and/or portions of components. The
system may be operated in a by-pass mode (e.g., when the TESM in
the heat storage device 12 is in a liquid state), such as
illustrated in FIG. 6B. The system may be operated in a warm-up
mode, so that thermal energy is transferred from. the heat storage
device to the emission reduction device, such as the warm-up modes
illustrated in FIGS. 6C and 6D. The warm-up mode may use a fluid
from the emission source (e.g., an emission fluid), such as
illustrated in FIG. 6C. The system may include a fan or blower 33,
as illustrated in FIG. 6D. For example, the warm-up mode may use
the fan or blower 33 to circulate (e.g., in a closed-loop) a fluid
between the heat storage device 12 and the emission reduction
device 14, such as illustrated in FIG. 6D. The warm-up mode, such
as the warm-up modes illustrated in FIGS. 6C and 6D, may be
employed prior to starting an emission source. The warm-up mode,
such as the warm-up mode illustrated in FIG. 6C, may be employed in
a warm-up mode that includes the flow of an emission fluid.
[0078] The emission reduction system may include an emission
source, an emission reduction device, a heat storage device, one or
more valves, an exit point, and a blower, fan, vacuum, or injector
all in fluid communication, such as in the emission reduction
system illustrated in FIGS. 7A, 78, and 7C. The emission reduction
system may be capable of operating in a warm-up mode for
transferring, heat from the heat storage device 12 to the emission
reduction device 14, such as using the configuration illustrated in
FIG. 7A. For example, the warm-up operating mode may be
characterized by a blower, fan, vacuum, or injector 33 forcing a
fluid to flow from an exit point (e.g., an opening to the
environment) 36 through the heat storage device 12, and later
through the emission reduction device 14. The emission reduction
system may be capable of operating in a charging mode for
transferring heat from an emission fluid to the heat storage
device, 12, such as using the configuration illustrated in FIG. 7B.
As illustrated in FIGS. 7A and 7B, the charging mode and the
warm-up mode may use the same connectivity between the emission
reduction device 14 and the heat storage device 12 and may differ
in the direction of the flow of fluid between the two devices. The
emission reduction system may be capable of operating in a by-pass
mode, such as using the configuration illustrated in FIG. 7C. The
system may be able to switch from a charging mode to a by-pass mode
by changing the position of one or more valves, 22, such as by
changing a by-pass valve 22 so that the emission fluid by-passes
the heat storage device 12. The system may include one or more
valves for controlling whether a fluid flows through or by-passes a
blower, fan vacuum, or injector 33.
[0079] The emission reduction system may include one or more
connections to an emission source, one or more heat storage device,
one or more emission reduction systems, one or more exit points,
and two or more valves, such as illustrated in FIGS. 8A, 8B, 8C,
8D, and 8E. The emission reduction system may be capable of
operating in a warm-up mode for transferring heat from the heat
storage device 12 to the emission reduction device 14, using a
system that includes two or more valves 22, 22', such as
illustrated in FIGS. 8A, 8B, and 8C. The warm-up mode may employ a
blower, fan, vacuum, or injector 33 for circulating a fluid through
a closed loop including the heat storage device 12 and the emission
reduction device 14, such as illustrated in FIG. 8A. As such, the
warm-up mode may be characterized by a blower, fan vacuum, or
injector 33, a heat storage device 12 and an emission reduction
device in fluid communication. The warm-up mode may be
characterized by a closed loop including a blower, fan, or vacuum
33, a heat storage device 12 and an emission reduction device 14.
The warm-up mode of operating the system may employ the emission
fluid or another fluid provided by the connection to the emission
source, as illustrated in FIG. 8B. For example, a fluid may flow
through the heat storage device 12 and later through the emission
reduction device 14 before flowing through the exit point 36, such
as the flow illustrated in FIG. 8B. As another example, the system
may employ a fan or blower 33, for flowing a fluid from the exit
point 36, later to through the heat storage device 12, and later
through the emission reduction device 14, such as illustrated in
FIG. 8C. The system may be capable of operating in a charging mode,
where an emission fluid flows through the emission reduction device
14 prior to flowing through the heat storage device 12, such as
illustrated in FIG. 8D. Although a configuration where the emission
fluid flows through the heat storage device 12 prior to flowing
through the emission reduction device 14, such as illustrated in
FIG. 8B, may be employed for the charging mode when the temperature
of the emission fluid is greater than the temperature of the heat
storage device, it may be advantageous to flow the emission fluid
through the emission reduction device 14 prior to flowing through
the heat storage device 12 so that the temperature of the emission
fluid flowing through the emission reduction device is maximized.
The system may be capable of operating in a by-pass mode, where at
least a portion of the emission fluid by-passes the heat storage
device 12, such as illustrated in FIG. 8E.
[0080] During the charging mode of operation where the emission
fluid flows through the emission reduction device 14 prior to
flowing through the heat storage device 12, it has surprisingly
been found that the temperature of the emission fluid may increase
while in the emission reduction device. As such, the temperature of
the emission fluid entering the heat storage device 12 may be
higher than the temperature of the emission fluid entering the
system. For example, when flowing through the emission reduction
device 14, the temperature of the emission fluid may increase by
about 5.degree. C. or more, about 10.degree. C. or more, about
15.degree. C. or more, or about 20.degree. C. or more.
Advantageously, the higher temperature of the emission fluid after
flowing through the emission reduction device 12 may allow for the
heat storage device to be heated faster, to store more heat, or
both. Without being bound by theory, it is believed that one or
more exothermic reactions, such as an oxidation reaction (e.g., an
oxidation of carbon monoxide, a hydrocarbon, or both) may occur in
the emission reduction device 12 resulting in the increase in
temperature of the emission fluid.
[0081] The systems, devices and processes according to the
teachings herein may advantageously be used for cold-starting an
emission source. Cold-starting of an emission source occurs after a
period of non-use such that the temperature of the emission source,
the temperature of the emission reduction device, or both has
decreased substantially compared to the temperature during
continuous operation. For example, immediately prior to the
cold-starting of the emission source, the temperature of the
emission source, the emission reduction device, or both may below
the lower limit operating temperature of the emission reduction
device. The lower limit operating temperature of the emission
reduction device may be the minimum temperature at which the
emission reduction device is efficient in reducing the amount of
the one or more undesirable chemicals. At the lower limit operating
temperature, the emission reduction device may reduce the amount of
an undesirable chemical by about 50% or more, preferably by about
80% or more, more preferably by about 90% or more, even more
preferably by about 95% or more, and most preferably by about 99%
or more. At the lower limit operating temperature, the emission
reduction device may reduce substantially all, or even entirely all
of the one or more undesirable chemicals.
[0082] The cold-starting of an emission source may occur when the
temperature of an emission source, an emission reduction device, or
preferably both is at or near ambient temperatures. By way of
example, the cold-starting of an emission source may occur when the
temperature of the emission source is about 50.degree. C. or less,
about 30.degree. C. or less, about 0.degree. C. or less, or about
-20.degree. C. or less.
[0083] When the emission source is a combustion engine of a
vehicle, cold-starting may occur after the engine has been off for
about 5 minutes or more, about 20 minutes or more, about 1 hour or
more, or about 3 hours or more. It will be appreciated that the
time for the emission source and/or the emission reduction device
to cool (e.g., below the lower limit operating temperature of the
emission reduction device) may depend on the ambient temperature,
the thermal mass, the initial temperatures, and the rate at which
the thermal energy is removed. The rate at which thermal energy is
removed may depend on whether the vehicle is in motion (and its
velocity). Cold-starting of an engine may occur after a vehicle has
been parked, with the engine off. Cold-starting of an engine may
occur while a vehicle is in motion, such as in a hybrid vehicle
where the engine may operate intermittently, or in a range-extended
electric vehicle where the engine may be turned on while the
vehicle is being powered by its electric battery that is nearing
charge depletion.
[0084] The emission reduction system preferably is capable of
reducing the emission of carbon monoxide, such as during the first
30 seconds after cold starting an emission source. More preferably,
the emission reduction system is capable of reducing the emissions
of carbon monoxide discharged from the system during the first 30
seconds after cold starting an emission source by at least about
20% compared to a system without a heat storage device for heating
the emission reduction device and only uses the heat directly from
the emission source and carried by the emissions to heat the
catalytic converter, wherein the cold starting occurs when the
ambient temperature, the initial temperature of the emission
source, and the initial temperature of the emission reduction
device are all about 25.degree. C.
[0085] A preferred article 50 that may be employed in a heat
storage device is an articles having one or more sealed spaces for
storing TESM and a fluid passage 16 for flowing a fluid, such as
the article illustrated in FIG. 9A. The article for containing a
TESM may include a first sheet 54 and a second sheet 56, such as
illustrated in FIG. 9B. The sheets 54, 56 may be sealingly attached
about an outer periphery 58 and about an inner periphery 60 (e.g.,
the periphery of the article near the fluid passage 52). The first
sheet 54, the second sheet 56, or both may include one or more
grooves or channels 62, such so that a fluid may flow between the
outer periphery 58 and the inner periphery 60. The article may have
an outer edge 64. The article may include one or more sealed spaces
66 that contain a TESM.
[0086] FIG. 10 illustrates features of a cross-section of an
exemplary heat storage device 80 having a plurality of articles 50
each having thermal energy storage material 74 encapsulated in a
plurality of sealed spaces 66. The articles may be arranged in an
insulated container 82, such as a container having a generally
cylindrical shape. The device may include an article 50(a) having a
first adjacent article 50(b) and a second adjacent article 50(c).
The article 50(a) and its first adjacent article 50(b) may be
arranged with one surface generally in contact. The article 50(a)
and the second adjacent article 50(c) may have generally mating
surfaces and may be arranged so that they partially nest together.
A spacer (not shown) may be used to maintain a distance between the
article 50(a) and its second adjacent article 50(b) so that a heat
transfer fluid (e.g., the emission fluid) can flow through a radial
flow path 83 in a generally radial direction between the two
articles, 50(a) and 50(c). The space between the article 50(a) and
the second adjacent article 50(c) may be part of a passage for
flowing a fluid, such as the emission fluid, through the heat
storage device. As illustrated in FIG. 10, each article may have a
surface that is in contact with a portion of the passage for
flowing the fluid through the heat storage device so that the fluid
can be in direct contact with each article and preferably each
sealed space. As illustrated in FIG. 10, the flow through the heat
storage device may include a radial flow path 83. Each radial flow
path 83 may have the same length, the same cross-section, or even
may be congruent. One or more of the articles may have an opening
near its center. The openings through the articles may also be part
of the fluid passage through the heat storage device. The articles
50 may be arranged so that their openings form a central axial flow
path 84. The space between the outer periphery of the articles 50
and the interior surface of the container 85 may also be part of
the fluid passage through the heat storage device and may form an
outer axial flow path 86. The heat storage device may have a first
orifice 87 that is in fluid connection with the central axial flow
path 84. The heat storage device may have a first seal or plate 88
that separates the first orifice 87 from the outer axial flow path
86. The container 82 may have a second orifice 89 which may be on
the same side of the container as the first orifice 87, or on a
different side of the container, such as illustrated in FIG. 10.
The heat storage device may have a second seal 90 that separates
the second orifice 89 from the central axial flow path. The first
seal, the second seal, or both may prevent a fluid from flowing
between the two axial flow paths 84 and 86, without flowing through
a radial flow path 83. With reference to FIG. 10, a fluid flowing
between the first orifice 87 and the second orifice 89 must flow
through a portion of the central axial flow path 84, and through a
portion of the outer axial flow path 86. The heat transfer fluid
must also flow through one of the radial flow paths 83 between
flowing through the two axial flow paths 84, 86. The sizes of the
two axial flow paths preferably are selected so that the hydraulic
resistance of the fluid is generally constant regardless of which
radial flow path a portion of the fluid takes. As such, the flow of
the heat transfer fluid through the heat storage device is
preferably a Tichelmann system. The container 82 preferably is
insulated. For example, the container may have an inner wall 91 and
an outer wall 92 and the space between the two walls 93 may be
evacuated and/or filled with one or more insulating materials. The
device may also have one or more springs, such as one or more
compression springs 94, that exerts a compressive force on the
stack of articles.
[0087] Furthermore, the present invention may be used in
combination with additional elements/components/steps. For example
the system may include a turbine to convert a part of the heat
captured from the exhaust gas waste heat into useful mechanical or
electrical work and thus improve the overall fuel efficiency of the
vehicle.
[0088] It will be appreciated that the heat storage device may be
further employed to heat one or more components in addition to the
emission reduction device.
[0089] While the present invention may be susceptible to various
modifications and alternative forms, the exemplary embodiments
discussed above have been shown by way of example. However, it
should again be understood that the invention is not intended to be
limited to the particular embodiments disclosed herein. Indeed, the
present techniques of the invention are to cover all modifications,
equivalents, and alternatives falling within the spirit and scope
of the invention as defined by the following appended claims.
* * * * *